Apparatus for producing multicom-ponent filaments and yarns



Oct. 5, 1965 J. 1.. RILEY ETAL 3,209,402

APPARATUS FOR PRODUCING MULTICOMPONENT FILAMENTS AND YARNS 2Sheets-Sheet 1 Filed March '7, 1962 Oct. 5, 1965 J. RILEY ETAL 3,209,402

APPARATUS FOR PRODUCING MULTIGOMPONENT FILAMENTS AND YARNS Filed March7, 1962 2 Sheets-Sheet 2 United States Patent 3,209,402 APPARATUS FORPRODUCING MULTICOM- PONENT FILAMENTS AND YARNS Jesse Louis Riley,Charlotte, N.C., and Joseph Ger-mane Santangelo, Morristown, and GregoryMartin Moelter, Basking Ridge, N.J., assiguors to Celanese Corporationof America, New York, N.Y., a corporation of Delaware Filed Mar. 7,1962, Ser. No. 178,060 8 Claims. (Cl. 18-8) This invention relates to anovel apparatus for producing multicomponent filaments and yarns. Moreparticularly, this invention relates to the production of multicomponentfilaments and yarns from a plurality of different component-formingmaterials. Each such component forming material is maintained in a zoneseparate from the zones of the other such materials and under asubstantially constant pressure, such pressure being of such magnitudeas to induce viscous or laminar flow rather than turbulent flow of astream of such material. A stream of component-forming material isremoved from each of such zones, and the streams are brought together ata common juncture to form a common stream having streamlined portionsmade up of the separate component-forming materials. The common streamis passed through a jet or spinnerette to thereby form a multicomponentfilament or a multicomponent yarn.

Multicomponent filaments and yarns are highly desirable because of theunique properties that can be obtained therein. For example, by theselection and incorporation of certain desired components into suchfilaments or yarns there can be obtained a resultant multicomponentfilament or yarn having specific desired end characteristics, e.g., suchend filament or yarn can be designed to exhibit certain dyeabilitycharacteristics, certain crimping characteristics, multicolor efiects,abrasion resistance, etc.

Heretofore, a number of dilferent apparatuses have been developed in anattempt to secure truly practicable means for the production ofmulticomponent filaments and yarns. However, such apparatuses haveproven complex and costly, and frequently have not resulted in theobtaining of satisfactory results. Typically, the apparatuses which havebeen used have required complicated valving systems, individual meteringpumps to introduce the various component-forming materials to the properspinning position, complicated jet assemblies, etc.

It is an object of the present invention to provide a simple yeteffective apparatus for the production of multicomponent filaments andyarns.

Another object of our invention is to provide an apparatus for theproduction of multicomponent filaments and yarns whereby individualmetering pumps for the introduction of each component-forming materialto the filament-forming jet are not required.

Additional objects will become apparent hereinafter.

Our invention will be best understood by the following description,taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic illustration of the apparatus of our invention asset up to produce a three component filament or yarn;

FIG. 2 is an enlarged sectional view taken along the line 22 of FIG. 1;

FIG. 3 is a schematic illustration of our apparatus arranged to producea filament or yarn made up equally of two components;

FIG. 4 shows an alternative arrangement to produce a two componentfilament or yarn wherein one component predominates;

3,209,402 Patented Oct. 5, 1965 "ice FIG. 5 illustrates apparatus foranother embodiment of our invention wherein one component-formingmaterial is fed as a sheath about a core of another componentformingmaterial;

FIG. 6 is a plan view showing the face of the spinerette used in theapparatus of FIG. 5;

FIG. 7 is a schematic illustration of apparatus arranged for dryspinning; and

FIG. 8 is a schematic illustration of apparatus arranged for wetspinning.

In accordance with one aspect of our invention, an apparatus is providedfor the production of multicomponent filaments and fibers. For theformation of a three-component filament or yarn apparatus is assembledas schematically illustrated in FIG. 1. The apparatus, generallydesignated by the reference numeral 10, comprises three separate lowpressure drop chambers or manifolds 12, 14 and 16. Separate conduits orpipes, 18, 20 and 22 communicate with chambers 12, 14 and 16,respectively. These separate conduits terminate and join together at acommon juncture point 24 to form a common conduit 26, which ultimatelyterminates at a filament-forming jet 28. Between common juncture point24 and jet 28 are disposed a throttle valve 30 and a two-Way valve 32,each being operatively associated with common conduit 26. A second jet34, communicates with two-way valve 32 through conduit 33.

Means, e.g., metering pumps 38, 40 and 42 are provided for introducingthe desired component-forming materials A, B and C, at appropriate flowrates into chambers 12, 14 and 16, respectively. Such metering pumpscommunicate directly with the chambers. Means are provided formaintaining component-forming materials A, B and C at constant pressureswithin chambers 12, 14 and 16 respectively. As illustrated in FIG. 1,such constant pressure means comprise separate surge tanks 44, 46 and48, which are fitted with spring actuated pressure pistons 50, 52 and54, respectively. Surge tanks 44, 46 and 48 communicate with chambers12, 14 and 16 through channels 56, 58 and 59, respectively.

While FIG. 1 illustrates the use of three separate surge tanks 44, 46and 48 to maintain constant pressures in chambers 12, 14 and 16,respectively, a single constant pressure source could also be employed,such single source communicating with each chamber. Further, instead ofusing spring-actuated pistons to obtain such constant pressures, othermeans could be employed, e.g. a weighted piston or a constant head tankor the like.

To operate our apparatus, metering pumps 38, 40 and 42 are actuated tothereby pump component-forming materials or dopes A, B and C from theirstorage tanks (not shown) and at preselected flow rates into chambers12, 14 and 16 until dynamic equilibrium conditions are attained.Spring-actuated pistons 50, 52 and 54 in surge tanks 44, 46 and 48ensure the maintenance of constant pressures in each of thecomponent-forming materials A, B and C contained in chambers 12, 14 and16. Separate streams of dopes A, B and C are pressure driven to passthrough conduits 18, 20 and 22, respectively, the flow rate of each suchstream being determined by the pressure differential between thepressure within the chamber containing the component-forming material ofsuch stream and the pressure outside the jet 28 and also by thecrosssection and length of the conduit leading off from such chamber. Itis of critical importance that such flow rate be of viscous or laminarcharacter rather than turbulent. That is, the streams ofcomponent-forming materials passing through conduits 18, 20 and 22 mustbe flowing in streamlined fashion so they arrive at a common juncture 24and unite with each other. The streamlined character of flow of eachstream will then persist in the common stream as it flows throughconduit 26. Such streamlined flow is readily obtained by (l) appropriateadjustment of the magnitude of the constant pressure within the chamberof manifold and/ or (2) adjustment of the crosssectional area and lengthof the conduit leading off from such chamber.

When a plurality of dope streams, or streams of other fiber formingmaterial, each of which is traveling in viscous flow, are broughttogether to form a single common stream, the interfaces between thedifferent streams remain stable. This permits the feeding of such commonstream to a jet to thereby obtain a multicomponent filament or yarnwherein the lines of demarcation between the variouscomponents persistand are preserved in the final product.

If a multicomponent filament is desired, the common stream (consistingof a plurality of streams of component-forming materials) is fed througha jet 28 having a single orifice, whereby each component retains itscharacter and is identifiable in the resulting multicomponent filament.On the other hand, in order to obtain a multicomponent yarn, aspinnerette 60 (FIG. 6) having a plurality of orifices is substitutedfor single orifice jet 28 and the common stream is fed therethrough.Thus, to obtain a three component yarn the common stream formed fromcomponent-forming materials A, B and C (FIG. 2) is fed to spinnerette 60whereby material A passes through the orifices in zone A, B through theorifices in Zone B, and C through the orifices in zone C. All of thefilaments thus formed are collected together thereby forming athree-component yarn.

The denier of the ultimate multicomponent filament or yarn is controlledby suitable adjustment of throttle valve 30. Thus, the finer the denierdesired, the tighter the valve position to thereby reduce thecross-section of the common stream flowing in conduit 26 as it passesthrottle valve 30 and prior to its extrusion through jet 28. 7

Of course, instead of single conduits 18, 20 and 22 extending from eachof chambers 12, 14 and 16, respectively, a plurality of conduits maycommunicate with each of such chambers. In this manner, thecomponentforming material within each chamber can be tapped off atnumerous points and can hence supply a plurality of jets 28. However, itis essential that the pressure within any such chamber remainsubstantially constant so as to insure uniform flow rates. Therefore,and in accordance with another aspect of our invention, for each jet 28,a second jet 34, which jet functions essentially as a dummy jet, isconnected to two-way valve 32 through a conduit 33. Jet 34 offersresistance to viscous fiow equivalent to that offered by jet 28. When itis desired to alter the nature of the multicomponent filament bysubstituting for jet 28 another jet having a different sized orificetherein, the portion of two-way valve 32 is simply reversed so as to cutoff the flow of the common stream to jet 28 and divert it through dummyjet 34. The jet 28 is removed, a new or different jet is placed inposition and valve 32 is reversed to thereby readmit the stream throughthe new jet. By virtue of this construc tion the pressures in chambers12, 14 and 16 remain constant even though one or more jets 28 is takenoff stream.

The particular processing technique utilized in forming themulticomponent filament or yarn from the common stream as it passesthrough the jet is not critical. Thus, the usual dry or wet processingtechniques may be employed, or dopes of molten polymers can be meltextruded through the jet. If the filament is wet processed theparticular composition of the bath will of course vary depending uponthe nature of the filament or yarn and the end characteristics desiredtherein.

The component forming materials or dopes may be solutions which maycontain the same filament-forming substance in solution but differ inthe kind of solvent or the concentration of the filament-formingsubstance. The materials may be polymeric substances which differ intheir degree of polymerization or degradation; in the case of celluloseor its derivatives, the two solutions can be produced from thecelluloses of different origin, for example one from cotton linters andthe other from wood pulp. In the case of solutions which undergo aripening process, such as viscose, differences in degree of ripeness maybe the sole difference or one of several differences (which may includealso cellulose content, sodium hydroxide content, carbon disulfidecontent) between solutions.

The material may comprise the same or different substances, but diiferin that one contains incorporated therein, either suspended therein ordispersed therein, such as by true or colloidal solution or byemulsification, at least one substance which is not of itself afilament-forming substance. Alternatively, the materials can contain oneor more of such additions in different concentrations. Such additionscan be solid, liquid or gaseous, for example pigments, rougheningagents, softening agents, agents for improving the feel, fats, oils,soaps, resins, dyestuffs, fungicides, medicinal substances,phosphorescent substances, and substance which can react chemically withthe spinning substance in the solution or during the precipitation. Onepolymer may contain sites, such as sulfuric acid groups, to enhance thebasic dyeing of the component fiber. In particular, those additionswhich are used to modify the properties of the filaments and havehitherto involved unavoidable disadvantages when applied to homogeneousfibers can be restricted to that zone of the filament where they aredesired. For example, pigments and delustrants can be introduced into adope for the purpose of roughening the filament, or of coloring ordulling the filament to cause a sensible decrease in the strength.

When our process is carried out with dopes which contain differentsubstances in solution, the substances can be chemically related as, forexample, two different cellulose esters, or a cellulose ester and acellulose ether, or two different albuminous substances. Substances may,however, be used which belong to quite different classes of bodies, suchas cellulose and an albuminous substance, or a cellulose ester or etherand an artificial resin or rubber produced by polymerization. The onlylimitation is that at least two of the materials do not mutuallycoagulate each other and if wet spun, are coagulatable by a commoncoagulating medium. By using materials which shrink to a differentextent during precipitation, drying or after-treatment, there may beobtained, for example, strongly crimped threads. Also, one or more ofthe materials or solutions may consist of or comprise mixtures of two ormore filament-forming substances insofar as this is permitted by thecompatibility of the particular substances.

Various effects may be obtained by the incorporation of pigments or dyesinto one or more of the dopes.

It will be apparent that our invention provides great flexibility andversatility as regards the obtaining of a multicomponent filament oryarn. For example, the relative amounts of components A, B and C in athree component fiber (FIGS. 1 and 2) are readily controlled by simplyadjusting the flow rates of the streams in conduits 18, 20 and 22. Ifthe cross-sectional areas and lengths of each of these conduits are thesame, then the volume flow rates of the streams therewithin areproportional to the rates of introduction of dopes A, B and C intochambers 12, 14 and 16 and hence are proportional to the pumping ratesof metering pumps 38, 40 and 42. Accordingly, the flow rate of thestreams Within conduits 18, 20 and 22 is controlled and adjusted byappropriate regulation of such metering pumps. If a filament or yarn isdesired containing equal parts of components A, B and C, the pumpingrates are kept equal to one another. If a filament or yarn containing50% of component A and 25% each of compor'ients B and C is desired, therate of introduction of A into chamber 12 is kept at twice the rate ofintroduction of B and C into chambers 14 and 16, etc.

An alternative method of adjusting the volume flow rates of the streamsin conduits 18, 20 and 22 is simply to vary their respectivecross-sectional areas or lengths. This method offers the advantage ofusing'the same pumping rates for all three metering pumps, 38, 40 and42, yet still obtaining variable flow rates by varying thecross-sectional areas or lengths of conduits 18, 20 and 22. If desired,appropriate balancing devices may be also employed, which balancingdevices are equipped with suitable bleed oifs to compensate for anyvariable pressures in the system. Thus, the rate of delivery for certainpumps is relatively independent of the working pressure in the system,so that pressure compensators are then advisable.

FIGS. 3 and 4 illustrate another embodiment of our invention wherein atwo component filament or yarn is formed. FIG. 3 shows the formation ofa filament or yarn containing equal amounts of components A and B, theflow rate of dope A equalling that of dope B (the crosssectional areasof conduits 18 and 20 being equal). FIG. 4 shows the formation of afilament or yarn predominating in component A, the flow rate of dope Ain conduit 18 considerably exceeding the flow rate of dope B in conduit20. It will be understood that if the stream of dopes A and B is fedinto a jet containing a single orifice, a twocomponent filament isextruded. If instead the stream of FIG. 3 is fed to a spinnerette havinga plurality of orifices disposed in a circle (e.g., see FIG. 6), thenthrough half of these orifices dope A would be extruded, and through theother half, dope B. (If the stream of FIG. 4 were fed through such aspinnerette, then of course more filaments of dope A would be obtainedthan of dope B.)

FIG. 5 illustrates another embodiment of our invention wherein amulticomponent filament is formed from component-forming materials A and'13. Material A is introduced into conduit 62 by metering pump 64.Material B is introduced through conduit 66 into the center of thestream of material A by metering pump 68. The rates of introduction ofboth materials A and B is controlled such that their flow is laminar orviscous rather than turbulent in character. Accordingly, material Aforms a sheath stream about the core stream of material B. Little or nomixing of these two streams occurs. The common sheath and core stream isfed through filters 61 to spinnerette 60 (FIGS. 5 and 6), whichspinnerette contains a plurality of orifices, 70 disposed in circle. Ifthe sheath and core streams are fed at the same flow rates then the corestream of material B will extrude from that half of each orifice .70nearest the center of the spinnerette 60 and the sheath stream willextrude from the outer half of each such orifice. A two componentfilament made up of approximately 50% each of components A and B is thenformed by conventional wet or dry spinning techniques. By varying therates of introduction of each of the component forming materials intoconduit 62 (and to spinnerette 60) the relative amounts of each of thematerials in the resulting two .components filament can readily bevaried within any desired limits, e.-g., less than 5% to in excess of95%, or more preferably from about 10% to 90% It will be understood thatthis sheath-core embodiment is not limited to formation of onlytwo-component yarns. Thus, while FIG. 5 illustrates formation andextrusion of a common stream consisting of a core of material Bsurrounded by a single sheath of material A, if desired, a second sheathof component-forming material C (not shown in FIG. 5) could be placedaround sheath A so as to have a three component stream which, whenextruded through the orifices 70 and spinnerette 60 would result in theformation of three component filaments. The relative amounts ofcomponents A, B and C therein would, of course, depend on their relativeflow rates. In like manner "n number of different component-formingmaterials can be introduced through the orifices of spinnerette 6 60 toproduce a filament having n different components. We have found thatbest results are obtained when it does not exceed 5.

The principle of the sheath-core embodiment of our invention can beutilized to extrude from a spinnerette having more than one set oforifices disposed in a single circle. Thus, a two-component streamconsisting of a core stream of component-forming material A sheathedwith a stream of component-forming material B, further sheathed with astream of component-forming material A can -be extruded through aspinnerette having two sets of orifices disposed in two concentriccircles. If the flow rates of core stream A and outer sheath stream Aare kept the same and each such flow rate is half that of the flow rateof intermediate sheath stream B, then similar two-component filamentswill be produced from all orifices. By keeping the flow rates of corestream A and sheath stream A equal and varying the ratio of the feed ofintermediate sheath stream B to the sum of the feeds of core stream Aand sheath stream A, the proportions of A and B in the ultimate filamentcan be varied as desired.

If desired, two-component filaments can be extruded from a spinnerettehaving n sets of orifices disposed in n concentric circles, merely byarranging that the total number of separate component-forming streams,i.e., the sum of the core stream plus all of the sheath streams, equalsn+1.

Although the sheath core embodiment of our invention has been describedwith reference to individual metering pumps 64 and 68 (FIG. 5) for theintroduction of streams of A and B into conduit 62, it will be apparentthat the constant-pressure apparatus of FIG. 1 may be employed ifdesired. That is, the stream of B flowing in conduit 20 (FIG. 1) mayserve as a core stream and be introduced into the center of the streamof A flowing in conduit 18, whereupon the conditions are similar tothose illustrated in FIG. 5 in that conduits 18 and 20 (FIG. 1)correspond to conduits 62 and 66, respectively (FIG. 5 In this manner,there is no need for individual metering pumps, since the flow rates areproportional to the substantially constant pressures maintained in eachof the chambers 12, 14 and 16, etc.

It will be noted that, if desired, the core can be radially divided sothat it is made up of several different component-forming materials,while the sheath can be made up of a single component-forming material.By appropriate disposition of the orifice or orifices in the spinnerette, innumerable variations can be obtained in the multicomponentfilaments and/ or multicomponent yarns ultimately obtained.

Although in the various subsequent example-s the multi componentfilaments or yarns are obtained by dry spinning techniques using anarrangement such as that illustrated in FIG. 7, our invention is equallyadaptable to wet spinning techniques (FIG. 8), melt spinning, and thelike. Filaments and yarns having novel properties are readily obtainablethereby. Thus, if two different polymeric materials, each having adifferent rate of coagulation in the spin bath, are wet spun (FIG. 8),the structural characteristics of each component in the filament can bemade to differ markedly, thereby producing filaments having such novelproperties as three dimensional crimp and the like.

It will be apparent that by the practice of our invention the number ofcomponents obtainable in the resultant fiber or yarn is virtuallylimitless, i.e. as many separate streams of component-forming dopes areprovided as the number of components desired in the ultimate fiber.Thus, four, five or more component fibers can be produced using theprinciples of our invention.

The nature of the various individual component-forming dopes used may,of course, vary within wide limits. Suitable components in themulticomponent fibers or yarns obtained by our invention includecellulose acetate, cellulose triacetate, polyvinyl chloride,polyvinylidene chloride, polyacrylonitrile, polyvinyl acetate,polycarbonates such as e.g. the reaction product of bisphenol A andphosgene, polyolefins such as e.g., polyethylene, polypropylene, and thelike, polyesters, polyamides, polyurethanes, polyureas, etc.

As previously stated, the dope may comprise the desired filamentcomponent dissolved in a suitable solvent. The particular solvent usedwill, of course, depend upon the nature of the polymer being spun.Typical solvents include acetone, methylene chloride hydrocarbons suchas xylene for the polyolefins, etc. The amount of component dissolved inthe solvent may vary within Wide limits and will depend upon theparticular component used, the nature of the solvent, the particularcharacteristics desired in the resultant fiber, etc. In general, theamount of component dissolved in the solvent will be from about 8 to 35percent by weight, a more preferred range being from about to 30 weightpercent.

At typical formulation for two different dopes, one a bright dope, theother a dull dope, these dopes capable of forming a distinctive twocomponent fiber, comprises: (1) 17-25% cellulose triacetate dissolved ina mixture of methylene chloride and methanol (bright dope) and (2) amixture of 17-25% cellulose triacetate and 1.25% titanium dioxide (basedon the triacetate) dissolved in a mixture of methylene chloride andmethanol (dull dope).

It is important to not that the dope need not necessarily be a solutionof the component. That is, our invention also finds application in meltextrusion, wherein the dopes consist of molten polymers. Separatestreams of such molten polymers are brought to a common juncture pointand united as previously described, and the common molten stream isextruded through the jet in conventional manner.

After the multicomponent filament has been formed it can be furtherprocessed by any of the various prior art methods, depending upon theend results desired. Thus, a plurality of such filaments can be spun toproduce a yarn, etc.

The following examples will further illustrate our invention. All partsare by weight unless otherwise stated.

EXAMPLE I A two component filament composed of bright and dull cellulosetriacetate was dry spun using the apparatus shown in FIG. 1, onlychambers 12 and 14 being used. The bright dope consisted of 22.8%cellulose triacetate dissolved in a solution of 91% methylene chlorideand 9% methanol. The dull dope consisted of 22.4% cellulose triacetateand 1.25% titanium dioxide (based on the triacetate) dissolved in 91/9methylene chloride/methanol. The bright dope was delivered into chamber12 by pump 38, the dulle dope to chamber 14 by pump 40. The pumpingrates and pressures maintained in the chambers were such that the commonstream of the two dopes was delivered to single-orifie jet 28 at a flowrate of 2 cubic centimeters per minute. A plurality, i.e., three each,of taps 18 and 20 were taken oif chambers 12 and 14, respectively, sothat three two-component filaments could be formed. The common streamsflowing in each of conduits 26 were extruded through jets 28, each suchjet having an orifice of 0.036 in. in diameter, and then through 8 feetof air onto a ring spinning take-up unit. The jets and assembly weremaintained at about 70 C. by an electronically heated tape wound aroundthe jet and assembly. There resulted true two-component filaments, eachconsisting of about 50% bright triacetate and about 50% dull triacetate.The run was continued for about 4 /2 hours during which time thetwo-component composition of the filament was maintained.

EXAMPLE 2 Two component filaments composed of bright and dull triacetatewere dry spun using the arrangement shown in FIGS. 57. Bright dope (dopeB) consisting of 22.8% cellulose triacetate dissolved in 91/9 methylenechloride/methanol was metered around the inner circumference of line 62to form a sheath. The resulting sheath and core dope was fed to a 20hole spinerette. The twenty holes, each having a dogbone shape with across-sectional area of 1.1 sq. mm., were arranged on a single circle(FIG. 6) having a diameter of 0.75 inch. The long dimension of each holelay on a radius of the spinnerette. The spinnerette and assembly wereheated to 70 C. by means of an electrically heated tape wound around thespinnerette assembly. The pumps metering each dope delivered dope at arate of 2 cc./min. Twenty two-component filaments consisting of brightand dull triacetate were extruded thereby through 8 feet of air onto aring spinning take-up unit. The dark portion of each filamentcross-section is dull triacetate while the white area is unpigmentedtriacetate. This twenty filament yarn was spun for a period of'4 /2hours during which time the two component composition of the filamentswas maintained.

EXAMPLE 3 The extrusion arrangement used in Example 2 was mounted on thetop of a 23-foot long downdraft spinning column (FIG. 6). A 22% solidsdope consisting of triacetate having an acetyl value of 61.5 and anintrinsic viscosity of 2.2 measured as a 4.6% solution of regeneratedcellulose in cupriet-hylene diamine, 1.25 titanium dioxide (based on thetriacetate), and the balance being 91/9 methylene chloride/methanol, wasmetered into the system as dope B. Dope A was a 22% solution oftriacetate having an acetyl value of 62.1 and an intrinsic viscosity of2.11 measured as a 4.5% solution of regenerated cellulose incupriethylene diamine in 91/ 9 methylene chloride/methanol. The twodopes were metered at equal rates to a spinnerette provided with 15holes each 0.042 mm. in diameter dressed with the filters composed of 3layers of viscose fabric and 2 layers of Johnson and Johnson cellulosefiber filter paper LT-152. The filters caused no mixing of the two dopestreams, two component fibers being formed at the spinnerettecapillaries. Similarly, the demarcation between the two dope streams wassufliciently sharp that the corresponding phases in the extruded fiberswere not mixed even though the composite dope was extruded throughcapillaries having a small diameter. The spinnerette and assembly wereheld at a temperature of 70 C. The extruded two component fibers werecollected at the bottom of the spinning cabinet, which was heated to 70C., on a ring twister at a take-up speed of 200 m./min. Cross-sectionsof these filaments showed each filament contained a bright and a dullportion of triacetate. This yarn crimped heavily due to its bilateralcomposition when held relaxed at a temperature of 18 C. for one minute.It also crimped heavily on immersion in a mixture of 25/75 acetone-waterfor one minute followed by air drying in a relaxed state. Fibersextruded from either of the single dopes alone did not crimp whensubjected to the same two treatments. Two component fiber was also spunin the above described equipment from a 27% solids dope of secondaryacetate of 54.5 acetyl value in 95.5/4.5 acetone/water and a 21.6%solids dope of cellulose triacetate of 61.5% acetyl value in 91/9methylene chloride/methanol.

EXAMPLE 4 six alternating 50 and 400 mesh stainless steel screensmounted before the spinnerette, and is then extruded through aspinnerette having 10 holes of 0.015" diameter, which holes are disposedin a single circle. The pumping rate of the two pumps 64 and 68 aremaintained equal and of such magnitude that the resulting bilateralfilaments are taken up at a speed of about 400 meters per minute.

Filamentary material as used herein includes both filaments and yarns.

It is to be understood that the foregoing detailed description is givenmerely by way of illustration and that many variations may be madetherein without departing from the spirit of our invention.

Having described our invention what we desire to secure by LettersPatent is:

1. Apparatus for producing a multicomponent filamentary material, saidapparatus comprising at least two separate chambers, means forintroducing different component-forming materials into said chambers,separate conduit means communicating with each of said chambers andterminating at a common junction point, substantially constant advancingpressure means operatively associated with each of said chambersincluding means for varying the volume of each of said chambers, wherebythe pressures within said materials are maintained substantiallyconstant, said pressure means being positioned upstream of said junctionpoint, a filament-forming jet, and second conduit means communicatingwith said first-mentioned conduit means at said junction point andcommunicating with said jet.

2. Apparatus for producing a multicomponent filamentary material, saidapparatus comprising at least two separate chambers, means forintroducing diflerent component-forming materials into said chambers,separate conduit means communicating with each of said chambers andterminating at a common junction point, substantially constant advancingpressure means operatively associated with each of said chambersincluding means for varying the volume of each of said chambers wherebythe pressures within said materials are maintained substantiallyconstant, said pressure means being positioned upstream of said junctionpoint, a filament-forming jet, second conduit means communicating withsaid first-mentioned conduit means at said junction point andcommunicating with said jet, and valve means in said second-mentionedconduit.

3. Apparatus for producing a multicomponent filamentary material, saidapparatus comprising at least two separate chambers, means forintroducing difierent component-forming materials into said chambers,separate conduit means communicating with each of said chambers andterminating at a common junction point, substantially constant advancingpressure means operatively associated with each of said chambers wherebythe pressures within said materials are maintained substantiallyconstant, said pressure means being positioned upstream of said junctionpoint, a filament-forming jet, second conduit means communicating withsaid jet, valve means in said second mentioned conduit, two-way valvemeans between said valve means and said filament-forming jet, a secondjet of equivalent resistance to viscous flow as said filament-formingjet, and conduit means between said second jet and said two-way valvemeans.

4. Apparatus for producing a multicomponent filamentary material, saidapparatus comprising at least two separate chambers for containingdifierent component forming material therewithin, means for maintainingsubstantially constant advancing pressure in each of said chambersincluding means for varying the volume of each of said chambers, 21separate conduit for each of said chambers, each of said conduitsextending between its associated chamber and a common juncture for allof said conduits for passing separate streams of said com- 10ponent-forming materials to said juncture in merger thereat, saidpressure means being positioned upstream of said juncture point, afilament forming jet, and other conduit means extending between saidjuncture and said jet for passing said merged streams to said jet.

5. Apparatus for producing a multicomponent filamentary material, saidapparatus comprising at least two separate conduits of differentdiameters, one of said conduits disposed concentrically and coaxiallywithin a second of said conduits, means for introducing differentcomponent-forming materials into each of said conduits in laminar flow,and a spinnerette containing a plurality of orifices disposed about acircle having a larger diameter than that of said conduit of smallestdiameter, said conduits operatively communicating with said spinnerettewith the conduit of smallest diameter spaced some distance from saidspinnerette.

6. Apparatus for producing a multicomponent filamentary material, saidapparatus comprising a plurality of concentric and coaxial conduits,means for introducing different component-forming materials in laminarflow into said condiuts, and a spinnerette containing a plurality oforifices disposed about a circle having a larger diameter than that ofsaid conduit of smallest diameter, said conduits operativelycommunicating with said spinnerette with the conduit of smallestdiameter being spaced some distance from said spinnerette.

7. The apparatus of claim 6 wherein said spinnerette contains aplurality of sets of orifices, each said set disposed in a circle, saidcircles concentric with one another.

8. Apparatus for producing a plurality of multicomponent filamentarymaterials, said apparatus com prising at least two separate chambers,means for introducing different component-forming materials into saidchambers, a plurality of separate conduit means from each of saidchambers, each such conduit means from one of said chambers alsoterminally communicating with one of said conduit means from another ofsaid chambers at a common juncture point, substantially constantadvancing pressure means operatively associated with each of saidchambers including means for varying the volume of each of said chamberswhereby the pressures within said materials are maintained substantiallyconstant, said pressure means being positioned upstream of said junctionpoint, filament-forming jets, and a plurality of second conduit means,each of said second conduit means communicating with one of saidfirst-mentioned conduit means at said junction point and communicatingwith one of said jets.

References Cited by the Examiner UNITED STATES PATENTS 2,220,226 11/40Freudenberg et a1. 188 2,253,089 8/41 Nydegger 264176 2,386,173 10/ 45Kulp et a1 l8--8 2,522,526 9/50 Manning 188 2,804,645 9/57 Wilfong 18-82,883,261 4/59 McGeorge 1854 2,891,278 6/59 Cook 188 2,923,970 2/ 60Genovese l8-8 2,931,091 4/60 Breen l854 3,049,397 8/ 62 OShaughnessy264176 3,061,402 10/ 62 Sanders 264--176 3,112,986 12/63 Woodell 18-8FOREIGN PATENTS 1, 1 10,39 8 7/61 Germany.

760,179 10/ 5 6 Great Britain.

MARCUS U. LYONS, Primary Examiner.

MORRIS LIEBMAN, MICHAEL V. BRINDISI,

Examiners.

5. APPARATUS FOR PRODUCING A MULTICOMPONENT FILAMENTARY MATERIAL, SAIDAPPARATUS COMPRISING AT LEAST TWO SEPARATE CONDUITS OF DIFFERENTDIAMETERS, ONE OF SAID CONDUITS DISPOSED CONCENTRICALLY AND COAXIALLYWITHIN A SECOND OF SAID CONDUITS, MEANS FOR INTRODUCING DIFFERENTCOMPONENT-FORMING MATERIALS INTO EACH OF SAID CONDUITS IN LAMINAR FLOW,AND A SPINNERETTE CONTAINING A PLURALITY OF ORIFICES DISPOSED ABOUT ACYCLE HAVING A LARGER DIAMETER THAN THAT OF SAID CONDUIT OF SMALLESTDIAMETER, SAID CONDUITS OPERATIVELY COMMUNICATING WITH SAID SPINNERETTEWITH THE CONDUITS OF SMALLEST DIAMETER SPACED SOME DISTANCE FROM SAIDSPINNERETTE.